Mine was when I put C4 in Heck Gunderson's pocket, accepted his quest to save his son Ted, brought Ted back to him, when they got together I backed away and pulled the detonator trigger while hidden. It blew them both along with their bodyguards! You should have seen them all flying across that luxurious ballroom...

Ah, what other game is there where you can do this, FNV is truly a masterpiece..

Hm i would have to say it was when i was at Red rock canyon and i was walking on the highest point not even paying attention looking at something so then i look back at the screen(it was like where you see Wild coyete and road runner when the coyete goes off the cliff.) and then i looked down and i was falling down like 100 ft and i was like this aint good!! Then SPLAT hit the ground like a pancake.

The first time I ever killed Caesar. Brought Boone with me. Caesar goes down, Boone says an epic line.

I didn't actually believe what I'd heard so I had to reload the auto-save and do it again.

The time I put 8 C4 under a Securitron and blew him up hundreds of feet into the air. It took him about 6 seconds to fly back down, hitting the roof of the Tops Casino, managed by Swank.
The time I went fishing with my amigo Raul. We came back with lots of Lakelurk Meat. Strange though, we had to both reload our fishing poles with bullets. :ermm:
The time I went into Zion and came out with loot and left behind dead bodies of White Legs.
The time I killed General Gobbledegook. Hilarious!